STEREO/ Solar-B Science Planning Workshop

Turtle Bay, Oahu, Hawaii, November 15-18, 2005

 

Abstracts

 

William.T.Thompson.1@gsfc.nasa.gov submitted this abstract...

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The STEREO Science Center

 

William Thompson

 

The STEREO Science Center (SSC) at the NASA Goddard Space Flight Center will be the "one-stop shopping" location for STEREO data, observation plans, analysis software, and links to other mission resources.  Along with the other data products, a special "Space Weather Beacon" telemetry stream, relayed through an array of antenna partners coordinated by NOAA, will provide near-real-time images, radio, and in-situ data.  The SSC will be completely integrated into the Virtual Solar Observatory, and will also be involved with the Virtual Heliospheric Observatory and the Virtual Space Physics Observatory efforts.

 

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William.T.Thompson.1@gsfc.nasa.gov submitted this abstract...

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The FITS World Coordinate System, and its application to STEREO and Solar-B

 

William Thompson

L-3 Communications, NASA Goddard Space Flight Center

 

The World Coordinate System (WCS) is a recent addition to the FITS standard to allow more flexibility and accuracy to the way that coordinates are handled in FITS headers.  Use of the WCS provides a standard way to describe coordinates for all kinds of solar data--not just two-dimensional images, but also synoptic maps, R-Theta plots, spectra, time series, and more.  New software in the SolarSoft library supports the WCS formalism, and allows complex coordinates to be handled with a few simple calls.  This new solar coordinate system and software offers several advantages to the STEREO and Solar-B missions:

 

1.  Provides a standard method for encoding observer's position in FITS headers.

 

2.  Treats image coordinates in the full spherical sense--particularly important for the STEREO/SECCHI Heliospheric Imager.

 

3.  Allows multiple coordinate systems to be applied to the same data set, e.g. both cartesian and heliographic.  This is particularly useful for the STEREO coronagraphs and Heliospheric Imager, where one coordinate system can be used for tracking solar features, while an ecliptic coordinate system can be used for comets and NEOs.

 

4.  Handles non-linear spectral dispersion functions, which is useful for the Solar-B EUV Imaging Spectrograph (EIS).

 

5.  Handles cross terms between disparate coordinate axes, such as between spatial and spectral axes; again useful for Solar-B EIS.

 

In general, use of a standardized coordinate system will pave the way for more closely integrated software between missions.

 

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mancuso@to.astro.it, fineschi@to.astro.it submitted this abstract...
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Halo-CMEs as Probes of Coronal Magnetic Fields

Silvano Fineschi, Salvatore Mancuso
INAF - Osservatorio Astronomico di Torino, Italy

Coronagraphic measurements of pB from STEREO in combination with Earth-based metric radio observations may provide information on the
coronal magnetic field of the on-disk ambient corona crossed by Earth-directed halo CMEs.

Radio spectrographs would yield an estimate of the speed of CME-generated shocks. The shock speeds are then used to set upper limits to the coronal Alfvén speed above CME-generating active regions. Visible-light polarimetric observations from coronagraphs would yield information on the coronal electron density that, combined with the knowledge of the Alfvén speed, can be used to derive information on the magnetic field strength.

To date, this technique has been applied only to CMEs directed sideways from the Earth-Sun direction because coronagraphic observations were only available from this direction. The technique was also limited by projection effects. We will discuss how STEREO's new perspectives of the on-board coronagraphs will allow to extend this technique to halo CMEs - from the Earth point-of-view - and how the stereoscopy of these coronagraphic observations will help reducing the projection effects.

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ctrussel@igpp.ucla.edu submitted this abstract...

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Properties of Interplanetary Coronal Mass Ejections (ICMEs) at 1 AU over the Solar Cycle

 

C. T. Russell(1), L. Jian(1), and J. G. Luhmann(2)

(1)IGPP and ESS, UCLA; (2)Space Sciences Laboratory, UCB.

 

We classify Interplanetary Coronal Mass Ejections (ICMEs) into three groups depending on the behavior of the perpendicular pressure, which itself may be controlled by the impact parameter of the spacecraft passing through the ICME relative to the center of the flux rope. Though there may be some weak and spent ICMEs at 1 AU that do not have pressure signatures, in this study we examine only those with pressure signatures to identify and characterize “active” ICMEs, the stronger events. We give the occurrence rate, peak pressure and the maximum magnetic field of each of the three groups of ICMEs based on the study of 10 years WIND data, to determine if the concept of an impact-parameter dependent signature can explain the conventional wisdom that only about one-third of ICMEs are found to contain a magnetic cloud. In addition, we give the solar cycle variation (1995-2004) of the number of identified ICME events, the percentage of events with shocks, the distribution of the change in the velocity of events, and the distribution of the peaks of the magnetic field and total perpendicular pressure. The peak pressure grows over the rising phase of the solar cycle and becomes greatest at solar maximum, producing the strongest interaction with the Earth’s magnetosphere. We look forward to the launch of STEREO that will allow us to make two to three (using ACE or WIND) cuts through ICMEs, enabling us to establish the ecliptic longitude variation of these structures and to test our hypothesis that the pressure signature of ICMEs depends on the impact parameter.

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jlan@igpp.ucla.edu submitted this abstract...

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Properties of Stream Interactions at 1 AU over the Solar Cycle: Anticipating STEREO

 

L. Jian(1), C. T. Russell(1), and J. G. Luhmann(2)

(1)IGPP and ESS, UCLA; (2)Space Sciences Laboratory, UCB.

 

A Stream Interaction Region (SIR) is formed when a fast solar stream overtakes a slow stream. The signatures of SIRs evolve as they move away from the Sun. If the velocity jump is sufficiently large relative to the compressional wave speed, one or more shocks may arise. Based on the study of the WIND (1995-2004) data, we find that the occurrence rate of shocks at SIRs is over 28% on average, which is unexpected high at 1 AU. The number of SIR events varies little over the solar cycle. In order to address the effect of SIRs on geomagnetic activity, we also determine the solar cycle variation of the change in velocity from slow stream to fast stream, percentages of SIRs with forward shock or reverse shock or both, and the solar cycle variation of the maximum magnetic field and the peak total perpendicular pressure. We demonstrate that rotations of magnetic fields often occur at the sector boundary ahead of the SIR, that the north-south component of the magnetic field is typical

 ly highly fluctuating within the SIRs, and that the thickness of the interaction region varies. We also study the adiabatic and non-adiabatic heating at SIRs. The launch of STEREO will add two more observation points on either side of the WIND/ACE pair, enabling stream interaction to be probed only a day or so apart, and determine how steady are SIRs.

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tom.narock@gsfc.nasa.gov submitted this abstract...

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STEREO and the Virtual Heliospheric Observatory

 

T.W. Narock (1,2), A.Szabo (1), J. Merka (1,2)

1. NASA/Goddard Space Flight Center

2. L3 Communications, GSI

 

The Virtual Heliospheric Observatory (VHO) is enabling the search and retrieval of disparate data sets through a common interface.  We present

the current state of the VHO which includes multiple search techniques as

well as distributed data processing software.  Additionally, we focus on the

inclusion of the STEREO mission in the VHO.  We present the challenges brought about by STEREO and plans to meet them.

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jgluhman@ssl.berkeley.edu submitted this abstract...

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STEREO-IMPACT Data Sets and Plans

 

J.G. Luhmann, P. Schroeder, A. Davis, R.A. Mewaldt, C.T. Russell

and the IMPACT Team

 

STEREO IMPACT data sets include the integrated plasma and suprathermal electron, magnetic field, and solar energetic particle observations. We summarize the three basic products that we expect to provide, and the interfaces to them. These include comprehensive, full temporal, energy and angular resolution Level 1 science and housekeeping data (including burst mode) provided through a website in a variety of file formats (CDF, HDF, ASCII, FITS) and also through a SOAP-based application program interface, Level 2 "Key Parameter" data including important moments, anisotropies and fluxes of the particle data at 1 min time resolution, including magnetic field- and merged with similar PLASTIC and SWAVES Key Parameter data products- in CDF, Flat File or ASCII formats, and Level 3 special products including shock and ICME event identifications and characterizations. Plans for data browse and display tools, and integration with imaging and model results will also be described.

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david.webb@hanscom.af.mil submitted this abstract...

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Use of Coriolis SMEI Imaging Observations to Provide All-sky Context Observations for the STEREO Mission

 

David Webb; ISR, Boston College & AFRL, Space Vehicles Dir.

Bernard Jackson and Paul Hick; CASS, University of California- San Diego

 

There are few methods of tracking and studying transient disturbances in the heliosphere, such as CMEs, and steady-state, corotating structures, like streamers, beyond the field-of-view of a coronagraph. The Solar Mass Ejection Imager (SMEI) experiment, launched in January 2003 on the DoD’s Coriolis spacecraft, has proven that it can do so. It views nearly the entire sky every 102 minutes beyond an exclusion zone of ~20 deg. elongation from the Sun. SMEI has observed nearly 200 CMEs during its first two years of operation and the instrument continues to operate successfully. Presently, the near real-time pipeline processing of the SMEI data is of a quick-look nature in that it uses orbital difference images of partially calibrated frame data to detect and track CMEs. We are working on the development of near-real time pipeline processing using fully-calibrated images. These data will provide heliospheric maps having increased sensitivity, usually to the design photometric lim

 it of SMEI, and areal coverage compared to the present quick-look maps. These data will be used as input to 3D tomographic programs and space weather forecast models. We are working to make this calibrated pipeline processing available by the time of the STEREO mission so that the SMEI data can be used to provide timely all-sky context observations of nearly the entire sky. These near real-time maps should be particularly useful for context observations for the SECCHI Heliospheric Imagers and the STEREO in-situ instruments which will observe the heliospheric structures remotely and as they pass over each spacecraft. We describe the current status of the SMEI mission and data processing, and some key results of the analysis of CMEs observed by SMEI.

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krucker@ssl.berkeley.edu submitted this abstract...

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Combining remote sensing imaging observations (RHESSI, Yohkoh, Trace, etc.) with in-situ observations (WIND, ACE, Ulysses etc.) provides a strong diagnostic tool to investigate the origin of solar energetic particles. After a review of open questions, I will discuss how we can relate these measurements to STEREO and SOLAR B observations.

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shaugan@esa.nascom.nasa.gov submitted this abstract...

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Coordination of Joint Observations - Lessons from SOHO and visions for the future

S. Haugan, ESA RSSD

 

I summarise the lessons learned from coordinating SOHO observations with each other, with other missions (TRACE, RHESSI, Yohkoh, Ulysses) as well as with many ground based observatories (Sac Peak, SST, VLA, Nobeyama, etc). Based on these lessons, I then focus on possibilities for improving the process of coordination for the future, through new methods, technologies and strategies.

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yashiro@ssedmail.gsfc.nasa.gov submitted this abstract...

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S. Yashiro(1,2) and N. Gopalswamy(2)

1: The Catholic University of America

2: NASA/Goddard Space Flight Center

 

The coordinated Data Analysis Workshop (CDAW) has been a successful concept in extracting science by pooling and analyzing large disparate data sets. With the exponential growth of computational, storage and electronic communications, it has become possible to handle data of unprecedented size. The CDAW concept is here to stay because of the systems approach in solar terrestrial relationships, for which massive observational data from various spacecraft need to be analyzed. We participated in several CDAWs and organized three of the recent ones on solar eruptive events, solar energetic particles and geomagnetic storms. We briefly describe the organization and outcome of the CDAWs, especially in enhancing the science return from NASA missions.

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steven.t.suess@nasa.gov submitted this abstract...

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What has been learned from Ulysses-SOHO quadrature observations

 

S. T. Suess and G. Poletto, with A. Bemporad, D. Biesecker, H. Elliott, R. Esser, G. Gloeckler, B. Goldstein, Y.-K. Ko, J. Kohl, J. Lin, D. J. McComas, M. Neugebauer, S. Parenti, J. Raymond, P. Riley, M. Romoli, N. Schwadron, G. Simnett, and T. Zurbuchen

 

Prior to STEREO, remote observations of solar wind sources at the Sun and in situ measurement of the same plasma have been possible

only using quadrature observations with SMM or Solwind and Helios 1/2 or, more recently, with SOHO and Ulysses. Several new results

have been possible only because SOHO and Ulysses measure spectral diagnostics of the corona (SOHO) and composition / ionization

state in the solar wind (Ulysses). Some of these results include: (i) Slow wind accelerates over a longer distance than fast wind.

(ii) Small coronal holes produce slower wind than large coronal holes. (iii) The acceleration gradient is smaller in small than in

larege coronal holes. (iv) And, for CMEs, measuring solar wind composition and charge state is necessary for finding the ejecta

in the solar wind and analyzing the physics of the sources. We have recently made such an identification for an ICME at Ulysses

beyond 4 AU and have been able to relate high charge state Fe to a reconnecting current sheet at 1.7 Rsun in the corona long after

a CME. Similar ionization and charge state measurements will be made with STEREO and they will be necessary for ICME ejecta

identification. We will summarize these results from our SOHO-Ulysses quadrature observations.

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steven.t.suess@nasa.gov submitted this abstract...

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Ulysses' orbit in 2006-2008

 

S. T. Suess and the Ulysses Project

 

To enable STEREO/ACE/WIND/SOHO/Ulysses coordination planning, it is necessary to know the location of Ulysses relative to the

Earth (ACE, WIND, SOHO) and the two STEREO spacecraft. Plots of the Ulysses orbit in the Sun-Earth frame of reference will be

shown. These illustrate that Ulysses will be unusually favorably located for supporting the STEREO mission in winter 2007 and,

again, in winter 2008. Specifically, otherwise ~two week SOHO-Ulysses quadratures last five months during these years. Assuming STEREO launch in April 2006, the locations of the STEREO spacecraft at these times will allow comprehensive, nearly tomographic, imaging of solar wind limb sources directed at Ulysses.

 

In summer 2007, when Ulysses passes the equator at 1.34 AU, it will be in near-radial alignment with Earth/ACE/WIND/SOHO.

This will permit analysis of radial gradients, advection, and propagation in the solar wind in the inner solar heliosphere.

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schwenn@mps.mpg.de submitted this abstract...

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Lessons for STEREO - learned from Helios.

Rainer Schwenn, MPS Lindau, Germany

 

The Helios mission resembled the upcoming STEREO mission in several respects. Helios could reveal details about the longitudinal and latitudinal stream structure, it allowed unique associations between limb CMEs and their radial propagation towards an in-situ observer, and the large-scale propagation of solar energetic particles could also be studied. It appears worthwhile to revisit the Helios data sets in order to otimize observations from STEREO.

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kusano@jamstec.go.jp submitted this abstract...

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K.Kusano(1), S.Inoue(2), D.Shiota(3), T.Yamamoto(4), Y.Miyoshi(2), T.Yokoyama(4), and T.Sakurai(5)

 

(1) The Earth Simulator Center, Japan Agency for Marine-Earth Science and Technology, Japan

(2) Graduate School of Advanced Science of Matter, Hiroshima Univ., Japan

(3) Kwasan and Hida Observatories, Kyoto University, Japan;

(4) Department of Earth & Planetary Science, University of Tokyo, Japan

(5) National Astronomical Observatory, Japan

 

The realization of the three-dimensional (3D) structure of magnetic field in solar active regions is crucially important to understand the mechanism of solar coronal activity, especially of the onset mechanism of flares. The numerical modeling based on the combination of the high-precision vector magnetograms provided by Solar Optical Telescope (SOT) onboard the up-coming Solar-B satellite and the high-speed super computer must be a powerful tool for this purpose. In this paper, first, we present the recent status of the 3D modeling and simulation of the active region dynamics. In particular, we focus on the study of the transition mechanism from pre-flare sigmoids to the onset of flare eruption, and show the new flare model that may account for the trigger process of flares as the nonlinear feed-back of the resistive tearing mode instability. Second, we discuss the prospect of the 3D modeling of the detail structure of active regions using the Solar-B and STEREO data.

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gdoschek@ssd5.nrl.navy.mil submitted this abstract...

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Science with the Solar-B Extreme-ultraviolet Imaging Spectrometer (EIS)

 

G. A. Doschek

 

ABSTRACT: EIS combines high spectral and spatial resolution with good-to-high time resolution and therefore represents one of the first of a new class of solar spectrometers that should greatly increase our understanding of physical processes in the solar atmosphere.  With the ability to observe in narrow-slit spectral raster mode and wide-slot spectral imaging mode, many diverse problems involving coronal processes can be investigated.  In this talk I will discuss several examples of science investigations using EIS, e.g., the co-spatiality of active region coronal loops that appear in spectral lines formed at different temperatures and the structure of soft X-ray solar flare loops.  These examples also indicate how data from the other Solar-B instruments and other spacecraft can be used to augment EIS science and how EIS can be used to augment investigations based primarily on data from other instruments.

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suematsu@solar.mtk.nao.ac.jp submitted this abstract...

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The aim of SOT is to provide data to investigate the physical coupling between the photosphere and the corona to ultimately understand the detailed mechanism of coronal dynamics and heating with the coordinated observations with X-Ray Telescope and EUV Imaging Spectrometer onboard SOLAR-B. With SOT we will be able to continuously observe solar atmospheric structures, especially photospheric magnetic structures, with a diffraction-limited spatial resolution of 0.2 to 0.3 arcsec and a polarization accuracy better than 1/1000; these performances are difficult to realize with ground-based instruments. We will present some major scientific objectives with SOT and its instrumentation to achieve them.

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nitta@notung.lmsal.com submitted this abstract...

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Lessons Learned from Yohkoh

 

The Yohkoh was the first of the missions launched since the 1990s that not only enabled us to monitor the dynamic solar corona nearly

continuously but also changed the way we do business.  Data from Yohkoh have produced renewed interests in magnetic reconnection and spawned some interdisciplinary research activities.  I will review some success stories about Yohkoh and things that could have been better, inducing discussion of how to maximize the science return from the STEREO and Solar-B projects combined.

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j.mcateer@grasshopper.gsfc.nasa.gov submitted this abstract...

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Solarmonitor.org is a real-time, Sun visualisation tool to provide multi-wavelength images of the solar disc from multiple space- and ground- based observatories. This will also provide flare- and CME- related parameters using advanced muliscale and mulitfractal analysis of these solar data. Solarmonitor.org is designed to be both highly redundant and scalable. Having already addressed issues of data access, management, storage and presentation we envisage a relatively straightforward evolution of the website to encompass both STEREO and Solar-B data as this becomes avaliable. This provides a real-time vital tool for science planners around the globe.

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terry.forbes@unh.edu submitted this abstract...

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Magnetic energy released by reconnection is thought to be responsible for both the acceleration of CMEs and the generation of flare radiation.  Together, Solar-B and Stereo will provide unprecedented observations not only of CME dynamics and flare radiation, but also of the reconnection site itself.  It is already clear from observations by Yohkoh, SOHO, and TRACE that Solar-B will be able to measure key properties of the plasma within the current sheet where reconnection actually occurs.  Such measurements will provide new constraints for both reconnection theory and for models of CME initiation and acceleration.

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ireland@grace.nascom.nasa.gov submitted this abstract...

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J. Ireland(1), C. A. Young(1), J. B. Noglik(2), R. W. Walsh(2)

 

(1)L-3 Communications Government Services Inc, NASA GSFC, Mail Code 612.5, Greenbelt, Maryland 20771, US

(2)Centre for Astrophysics, University of Central Lancashire, Preston, PR1 2HE, UK

 

This paper examines the double filter ratio method proposed recently by Chae et al. (2002), for determining temperatures in the solar atmosphere. Chae’s paper takes two filter ratios (TRACE 195/171  ̊A and 284/195  ̊A ) which, when plotted against each other, provide a colour-colour curve for determining a wide range of unambiguous plasma temperatures. We extend this method to SOHO/EIT data of a flare loop in an attempt to obtain the temperature profile along the structure. In doing so, we find Chae’s method to be troublesome with many data-points sitting off the colour-colour curve.  We examine some reasons why this might be the case.  We also examine statistical methods that assign a probability that the emission in any one pixel is due to a particular temperature.  This probabilistic view of the colour-colour temperature diagnostic attempts to quantify one source of uncertainty in our understanding of the temperature profile of coronal loops.  The implications of these observations for future broadband EUV imagers are discussed.

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hagino@kasi.re.kr submitted this abstract...

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M. Hagino, Y.-J. Moon, and Y.D. Park

 

Korea Astronomy and Space Science Institute

 

In this study we have examined the relationship between the chromospheric and coronal chirality using BBSO H-alpha and TRACE EUV 171A data of 61 active regions from June 1998 to Oct 2004. Using H-alpha filament channel structure, we identified the chromospheric chirality of filaments, known as "dextral" or "sinistral". When viewed from positive polarity side of the polarity inversion line, filament channels is dextral (sinistral) if the fibril goes to right (left) from the positive polarity, respectively (Martin, 1998). On the other hand, we determined the coronal chirality by examining the crossed dark and bright threads in EUV filaments, as suggested by Chae (2000). The comparison between the chromospheric chirality and the coronal chirality shows that the majority of dextral (sinistral) chromospheric chiralities correspond to negative (positive) coronal chirality, supporting Chae's Prediction.

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isuzuki@solar.mtk.nao.ac.jp submitted this abstract...

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Three Dimensional Motion of Plasmas Associated with Coronal Mass Ejections Observed with NOrikura Green-line Imaging System (NOGIS)

 

Suzuki, I.(1,2), Sakurai, T.(1,2), and Ichimoto, K.(2)

(1) Graduate University for Advanced Studies (Sokendai)

(2) National Astronomical Observatory

 

In order to investigate the structure and the driving mechanism of Coronal Mass Ejections (CMEs), it is important to examine in detail the magnetic field structure in the low corona. NOrikura Green-line Imaging System (NOGIS), with its unique capability of Doppler imaging, was used to study CMEs and its source regions observed on 1999 May 7 and 2005 July 28. In 1999 May 7 event, the source region consisted of two loop systems, a small loop system with a blue shift and a neighboring larger loop system. The small loop three-dimensionally moved toward the large loop and destabilized it, resulting in the CME with a red shift. In 2005 July 28 event, ejection of a small loop system with a red shift started from among neighboring larger loop systems. We suggest that the direction of mass ejection depends on the configuration of magnetic fields around the source region and the location of the initial energy release in the magnetic field configuration.

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moka@kwasan.kyoto-u.ac.jp submitted this abstract...

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Particle Acceleration in the Heliosphere --- Lessons from GEOTAIL

 

M. Oka(1) and T. Terasawa(2)

 

1: Kwasan Observatory, Kyoto University

2: Department of Earth and Planetary Science,

   The University of Tokyo

 

We present recent results on particle acceleration at interplanetary shocks and the Earth's bow shock obtained by the GEOTAIL spacecraft. In general, the acceleration mechanism is considered to be the so-called Diffusive Shock Acceleration (DSA) but there are some assumptions and simplification in the theory, and the detailed micro-scale plasma physics remains unclear. Interplanetary shocks associated with Coronal Mass Ejections (CMEs) serve as an excellent example against which to test conventional models of particle acceleration. It is shown that not only ions but also electrons are accelerated by the DSA process. The Earth's bow shock is also suitable for studying particle acceleration. Energetic diffuse ions are produced at the quasi-parallel region of the bow shock and high resolution data are available. The origin of these ions, their nonlinear reaction to the shock structure, and their transport process are to be discussed.

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binhest@linmpi.mpg.de submitted this abstract...

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We compare the performance of two alternative algorithms which aim to construct a force-free magnetic field given suitable boundary

conditions. For this comparison, we have implemented both algorithms on the same finite element grid which uses Whitney forms to describe the fields within the grid cells. The additional use of conjugate gradient and multigrid iterations result in quite effective codes.

 

The Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithms both perform well for the reconstruction of a known analytic force-free field. For more arbitrary boundary conditions the Wheatland-Sturrock-Roumeliotis approach has some difficulties because it requires overdetermined boundary information which may include inconsistencies. The Grad-Rubin code on the other hand loses convergence for strong current densities. For the example we have investigated, however, the maximum possible current density seems to be not far from the limit beyond which a force free field cannot exist anymore for a given normal magneticfield intensity on the boundary.

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binhest@linmpi.mpg.de submitted this abstract...

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Nonlinear force-free magnetic field extrapolations: Comparison of Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithms

 

Bernd Inhester, Thomas Wiegelmann

 

We compare the performance of two alternative algorithms which aim to construct a force-free magnetic field given suitable boundary conditions. For this comparison, we have implemented both algorithms on the same finite element grid which uses Whitney forms to describe the fields within the grid cells. The additional use of conjugate gradient and multigrid iterations result in quite effective codes.

 

The Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithms both perform well for the reconstruction of a known analytic force-free field. For more arbitrary boundary conditions the Wheatland-Sturrock-Roumeliotis  approach has some difficulties because it requires overdetermined boundary information which may include inconsistencies. The Grad-Rubin code on the other hand loses convergence for strong current densities. For the example we have investigated, however, the maximum possible current density seems to be not far from the limit beyond which a force free field cannot exist anymore for a given normal magnetic field intensity on the boundary.

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mweber@cfa.harvard.edu submitted this abstract...

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Scientific Objectives of the XRT

M. Weber, E.E. De Luca, L. Golub, and J. Cirtain

 

The X-Ray Telescope is a whole-Sun imager with 1 arcsec pixels and nine diagnostic filters spanning the range 6.1 < log T < 7.5. I will give an overview of the XRT's scientific capabilities and objectives, as well as some "science firsts" we may expect, in the context of the Solar-B mission.

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joseph.mazur@aero.org submitted this abstract...

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J. E. Mazur & J. B. Blake

The Aerospace Corporation

 

We will introduce an energetic particle spectrometer that is part of the in-situ measurement package for an upcoming TWINS mission of opportunity.  The instrument has asimilar energy range and species coverage to that of STEREO/IMPACT/LET.  Because of its highly-eliptical orbit, we will obtain another point for measurements of solar particle events and shocks at 1 AU to be compared with STEREO, as well as a means of studying multi-MeV particle access and trapping in the Earth’s magnetosphere.  There will be overlap in the STEREO and TWINS missions in 2006.

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nick.arge@hanscom.af.mil submitted this abstract...

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Solar Synoptic Maps: Their Construction and Uses

C. Nick Arge (AFRL/Space Vehicles Directorate)

 

Abstract: Solar synoptic maps are used for a wide variety of purposes ranging from the study of the long-term behavior of solar features (e.g., sunspots and coronal holes) to initializing and driving coronal and solar wind models (e.g., photospheric field observations). In this talk, I 1) describe a number of different types of solar synoptic maps and the advantages and disadvantages of each, 2) discuss some of the methods used to construct them, 3) show examples of the different types of solar disk and limb observations that are routinely assembled into synoptic maps, and 4) provide a few examples of how they are used to both initialize and drive as well as validate models. Experience has shown that by carefully assembling synoptic maps, taking into account effects not always included (e.g., solar b angle and polar field corrections), one can often significantly improve their usefulness, especially when applied to models. Finally, I discuss possible methods for improving solar wind forecasting at L1 using STEREO data.

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iguana@ucar.edu submitted this abstract...

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Observations obtained at the Mauna Loa Solar Observatory are presented and discussed in the context of their  complimentary and supporting scientific contributions to NASA missions such as STEREO, SOHO, TRACE and Solar-B. The Mauna Loa advanced coronal observing system is comprised of three instruments: PICS, CHIP and Mk4, which together record the solar chromosphere and low corona at a time resolution of 3 minutes and a time coverage of about 9 hours, on average about 340 days a year. PICS provides full disk and off-limb images of the sun in the neutral emission line of Hydrogen-alpha (656.3 nm), CHIP records the full solar disk and off-limb in the emission line of Helium-I (1083.0 nm) as well as full disk velocity images using Helium-I line center and wing observations. The Mk4 coronagraph records the low corona in white light, from 1.12 to 2.8 solar radii (as measured from sun center). We will present highlights of recent work using NASA and MLSO datasets and discuss plans to provide new data products that compliment NASA data as well as combine NASA and MLSO observations.

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linton@nrl.navy.mil submitted this abstract...

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The Role of Three Dimensional Topology in Magnetic Reconnection

 

M. G. Linton

 

I will discuss how the three dimensional structure of interacting magnetic fields plays a key role in the dynamics and energy release resulting from their reconnection. I will summarize numerical experiments of flux tube reconnection, focusing on how the field orientation and topology in three dimensions dramatically change the outcome of the experiment. These experiments could help us to better understand coronal reconnection events, given a good understanding of the three dimensional topology of the solar corona. The three dimensional observational capabilities of STEREO promise to be useful for determining this topology, and therefore for understanding and predicting coronal reconnection events.

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michael.hesse@nasa.gov submitted this abstract...

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STEREO modeling support at the Community Coordinated Modeling Center

 

Michael Hesse

CCMC, NASA/GSFC

 

The Community Coordinated Modeling Center provides to the research community, access to the output of modern space science simulations. Models at the CCMC are provided by the research community and cover the entire domain between the Sun and the Earth's upper atmosphere. Following a request by the STEREO science team, the CCMC has recently added to its support functions the routine provision of solar and heliospheric model output in support of STEREO research and operations. This presentation will provide a brief overview of CCMC's solar and heliospheric side. It will then focus on STEREO-specific support activities that are presently  underway. Finally, we will encourage further input from the STEREO and SOLAR-B communities in order to further tailor  the support CCMC provides.

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michael.hesse@nasa.gov submitted this abstract...

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The structure of the kinetic dissipation region in collisionless magnetic reconnection

 

Michael Hesse

NASA/GSFC

 

In the solar community, magnetic reconnection is considered to be one contender for efficient particle acceleration in flares and other solar eruptions. The efficiency of particle acceleration in magnetic reconnection depends strongly on the spatial dimensions of the reconnection region, and on the structure of the associated electric fields. In order to provide input into these particle accelerations studies, we provide in this presentation, an overview of the present state of knowledge of collisionless reconnection physics. In particular, we will discuss which scale sizes dominate the reconnection process in solar relevant cases, where  magnetic fields are not expected to vanish in the reconnection region proper. We will further show the associated electric field structures, and discuss the problem of coupling microscopic processes to the macroscopic solar coronal evolution.

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ryouhei.kano@nao.ac.jp submitted this abstract...

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The soft X-ray Telescope (XRT) aboard Solar-B will observe the solar corona with the high spatial resolution of 1 arcsec pixel. To reveal how coronal plasma is heated by photospheric magnetic activities, we will make coordinated observations by three instruments aboard Solar-B; XRT, SOT and EIS.  Because XRT is a grazing incidence telescope, it has the capability to take temperature maps at different temperatures from 2MK to 30MK by filter ratios. It is also possible to obtain TRACE-like low temperature (1MK) images as well. Based on Yohkoh/SXT operations, XRT has many autonomous functions which are useful for observations of active events. We will present the performance of XRT with some scientific objectives.

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vourlidas@nrl.navy.mil submitted this abstract...

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On the Measurement of Dynamical Properties of CMEs with the SECCHI Coronagraphs: Issues and Solutions

A. Vourlidas, R.A. Howard

 

With the complement of the coronagraphs and imagers in the SECCHI suite, we expect to be able to follow continuously a coronal mass ejection from the Sun to Earth for the first time. The comparison, however, of the CME emission among the various instruments is not as easy as one might think. This is because the coronagraphs record the Thomson scattered emission from the CME plasma which has a rather sensitive dependence on the geometry between the observer and the scattering plasma. In this talk, we will describe the issues that arise in comparing CME emission over a large range of elongation angles and will outline the solutions we will adopt for the SECCHI observations

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Pete.Riley@saic.com submitted this abstract...

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Interpreting STEREO Observations using Global MHD Models

 

Pete Riley, Jon Linker, Zoran Mikic, and Roberto Lionello

 

We use global MHD simulations of CMEs to anticipate the similarities and differences between measurements that will be made by the two STEREO spacecraft during the lifetime of the mission. In addition, we attempt to use these same simulated observations to reconstruct the three-dimensional properties of CMEs and the ambient solar wind. We assess the degree to which this is successful by comparing with the global simulation results. Finally, we demonstrate a prototype GUI-driven tool that merges STEREO spacecraft trajectories and viewpoints with our simulations to provide a global context for interpreting the STEREO results.

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masuda@stelab.nagoya-u.ac.jp submitted this abstract...

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What did we learn from the 11-year Yohkoh operations?

Satoshi Masuda (STEL, Nagoya University) and Tetsuya Watanabe (NAOJ)

 

The Yohkoh satellite had been operated by solar physicists ourselves from 1991 to 2001.  The operation system of Yohkoh is reviewed, and its advantages and disadvantages are summarized. This is important for considering the Solar-B operation. Also we introduce coordinated observations/researches between Yohkoh and ground-based observatories.

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cnkorendyke@ssd5.nrl.navy.mil submitted this abstract...

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Coordinated Solar B, STEREO and SOHO observations of the initiation and propagation of Coronal Mass Ejections

 

Clarence M. Korendyke

Naval Research Laboratory

 

The constellation of Solar B, STEREO and SOHO spacecraft allow us for the first time to obtain a complete set of observations of the lift off of a coronal mass ejection.  These type of observations may begin relatively early in the STEREO/Solar B mission once a 15 to 20 degree earth STEREO spacecraft separation is achieved and continue for the entire baseline mission.  The Secchi/STEREO observations will provide EUV and white light observations of the lift off in the plane of the sky and from another vantage point.  SOT/Solar B will provide vector magnetograms of unprecedented sensitivity and high resolution solar images.  EIS/Solar B will provide high cadence spectra of the early stages of the coronal mass ejection.  These spectra will provide the first velocity maps of a coronal mass ejection in the lower corona.  The velocity maps will have well defined temperature coverage.  XRT/Solar B and EIT/SOHO will provide high cadence images of coronal plasma evolution on the disk.

   Combined observations of EIT/EUVI/EIS in the 19.5nm passband are of particular scientific interest.  An initial set of observations is presented for discussion.

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simon.plunkett@nrl.navy.mil submitted this abstract...

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Lessons Learned from SOHO: The Role of SOHO in STEREO and Solar-B Mission Science

 

Simon P. Plunkett

Naval Research Laboratory

 

The SOHO mission has almost completed a full solar cycle of observing the Sun and its effects on the heliosphere. This talk will highlight advances in understanding the Sun from SOHO that can help to maximize the science return from STEREO and Solar-B. The talk will also focus on lessons learned from scientific planning and operations of the SOHO instruments that can be applied to the STEREO and Solar-B missions. There are significant differences in the concepts of operations for each of these missions, and the impact of these differences on planning and executing observational programs will be discussed. SOHO is expected to continue operating during the STEREO and Solar-B missions, and the ways in which SOHO can contribute to achieving the science objectives of both missions will be discussed.

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p.r.young@rl.ac.uk submitted this abstract...

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Using Solar-B/EIS - lessons from SOHO/CDS

 

P.R. Young, CCLRC Rutherford Appleton Laboratory

 

CDS and EIS share many similarities, both begin EUV imaging spectrometers with similar data formats and software. Telemetry restrictions for both instruments lead to spectral windowing being an important observation constraint, and analysis issues such as cosmic rays and velocity measurement are common. This presentation will provide the experiences learnt from almost 10 years of observations with CDS and how they can be applied to EIS. In addition, methods of coordinating EIS and CDS will be discussed, and the benefits of using both instruments together highlighted.

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alphonse.sterling@nasa.gov submitted this abstract...

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Observing Solar Eruptions with Solar-B and STEREO.

Alphonse C. Sterling

 

In recent years we have been observing the initiation of solar eruptions that involve solar filaments.  The filaments act as tracers for the evolution of the coronal magnetic field just prior to and just after the start of fast eruption.  We have primarily used data from SOHO/EIT, Yohkoh/SXT, and TRACE, and SOHO/LASCO along with hard X-ray data from various instruments and line-of-sight magnetograms from SOHO/MDI or Kitt Peak.  This work has allowed us to better understand the dynamics of magnetic fields leading up to eruption, including a "slow-rise" phase of filament movement and activation, and the transition from the slow-rise phase to the violent eruption.  Here we will explain how we will utilize high-time-cadence and high-spatial-resolution images, EUV spectroscopic data, and vector magnetograms of Solar-B, along with multi-angle white-light images from STEREO, to improve upon our understanding of the earliest stages of solar eruptions.  We will discuss prospects for using these new data to isolate the mechanism (or mechanisms) responsible for triggering the onset of fast eruption.

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russ.howard@nrl.navy.mil submitted this abstract...

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The SECCHI instrument suite is designed to observe coronal mass ejections from their launch at the Sun and track them through the corona and eventual impact at Earth.  Our prime science questions are being developed.  Data sets that will be available as part of the routine quick-look processing are the corrected images (Level 0.5), total brightness and percentage polarization images (Level-1), catalogues of the data, lists of CME (and other) events, movies and synoptic maps.  Software routines will be available to convert the images into Level-1 calibrated images. The data will be available via a web-based query tool, as well as through VxO queries.  Analysis tools to perform 2D and 3D analyses are also being developed.  The observations are intended to be synoptic in nature, but 20% of the telemetry has been allocated to special observations.  To fill those special observations, we have a series of planning meetings (web based) at quarterly, monthly and weekly intervals.  Anyone may submit a request for special observations – a web page will explain the procedure, but it is based on the SOHO JOP.  The synoptic observations will be carried out from both platforms, but the special observations may or may not, depending on the goal.  An example of such “special observations” might be a high cadence sequence trying to get higher cadence on the initial phases of the CME process.  The sequence might end by the on-board detection of a CME, which would freeze the circulating buffer.  The two spacecraft might not trigger on the detection of the CME at the same time, so those observations would be from one spacecraft alone.

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paulett.liewer@jpl.nasa.gov submitted this abstract...

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3D Sun Loop Tracer: A Tool for Stereoscopy of Coronal Loops for NASA's STEREO Mission

 

P. C. Liewer,  J. R. Hall, E. De Jong, J. Lorre, P. Sheth, JPL

Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 169-506, Pasadena, CA 91109

paulett.liewer@jpl.nasa.gov

 

Stereoscopy and triangulation can be used to determine the three-dimensional geometry of coronal loops seen in simultaneous images from the two STEREO spacecraft. Here we demonstrate a new tool, 3D Sun Loop Tracer (SLT), which uses stereoscopy to determine the 3D structure of a loop that can be identified in both images. SLT proceeds in several stages. First, the user “seeds” the tool by selecting the same loop in the two images of a stereoscopic pair. Next, the tool uses loop tracing algorithms and triangulation techniques to obtain the three-dimensional (x,y,z) coordinates of points on the loop. The tool has been developed and tested using a physics-based synthetic 3D coronal model (K. Schrijver, private communication). The tool has been shown to produce accurate results for loop reconstruction over a wide range of stereoscopic (separation) angles. The goal is to use this tool to analyze the evolution and stored magnetic energy in loops observed by the EUV instruments on the STEREO spacecraft. Once the loops have been reconstructed in 3D, they can be compared to non-potential magnetic field line extrapolations. We will discuss how Solar B observation can be utilized to make tiepointing more effective for STEREO.

 

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